Process of rating hides and skins



Patented Mar. 29, 1932 PATENT OFFICE mm. 1mm Gonna, or wonus, exams! PROCESS OF RATING RIDES .AN'D SKINS No Drawing.

This invention is based on the fact discovered atthe utilization of waste material from the tanyard, that the Waste ieces of animal hides, as used in large quantities for producing glue stuff, need not be submitted to the gluing process but, submitted in their natural state to a kind of automatic digestion (autolyzed) and then added to the hating liquor, produce an excellent effect for the 10 obtaining of the pelts previous to the dressing.

For the production of the self digestion,-

which is carried out best at about 20 to 30 C., no addition of any ferment, commonly used for hating, is necessary, this self digestion having to be limited to the hide waste, in order to preserve its proper characteristic at the steeping and limin or hating; it must further be interrupted efore the formation 20 of ammonia and examined as regards its effect, in order that no portion of the hides and pelts be damaged. It has been ascertained that those ferments and bacteria, which split up the glue stuif, might damage 25 in the lime-pit and hating process the hides and the pelts. These ferments and bacteria in the glue stuff. must consequently be previously rendered harmless, which is effected by commonly used preserving and drying anorganic salts, e. g. sulfates and chlorides of the alkalis. After a few days the hide L wastes have hydrolyzed, so that it can be Application med December 18, 1928. Serial no. 326,907.

easily separated from the hair. The self digestion and the extremely rich bacteria ac tivity are interrupted, and after preserving with toluol or by drying for instance with wood dust, the bacteria are separated in the usual manner from their ferments, the required hating strength is adjusted and before the utilization tested as regards its effort.

Ewample 1 5 Animal hides wastes (pieces) in natural conditioner from salted hides and skins, after softening same, are autolyz'ed at figures 2030 C. as described above. A reserved or dry extract obtained from a out 10 kilos pieces of hides is added to 3 litres of waterjn the tan-vat. The usual quantity of ready cleaned pelts is then put into this ready hating liquor.

Ewample 2 Extract produced from about 3 kilos selfdigested glue-stuff and tested as to the desired hating strengthis added to about 600 lit'ls of hating water together with the usual quantity of deliming material such as ammonia.- salts or organic acids. The ready pelts are. then put into this hating liquor.

n E sample 3 tainin sterile self-digested hide wastes and other eliming materlals.

3. The process of hating hides and skins which comprises subjecting the hides and 5 skins to the action of a bating liquor having sterile self-digested hide wastes added thereto in a dry condition and other albuminous substances in natural condition.

4. The process of hitting hides and skins m which comprises subjecting the hides and ,skins to the action of a batin liquor containin sterile self-digested hi e wastes and other ydrocarb'ons in natural condition.

In testimony whereof I aflix my signature.

KARL. HERMANN GGLLEB. 

